In comparison with inorganic lenses, plastic lenses have a higher refractive index and a higher Abbe number, are lighter and harder to break, and can be dyed and have thus rapidly become widespread in optical materials such as spectacle lenses and camera lenses. Various molded articles for lenses have been developed and used up to now.
Among these, representative examples include allyl resins obtained from diethylene glycol bisallyl carbonate and diallyl isophthalate, (meth) acrylic resins obtained from (meth) acrylate, and polythiourethane resins obtained from isocyanate and thiols.
In recent years, advances have been made in the development of plastic lenses having a function of cutting ultraviolet (UV) light.
In the related art, adverse effects due to exposure of the eyes to ultraviolet light are regarded as a problem. Furthermore, in recent years, the blue light included in natural light or the light emitted from liquid crystal displays of office equipment, displays of portable equipment such as smartphones or mobile phones, and the like has had an influence on the eyes, causing problems such as feelings of eye fatigue and pain and there is a demand to reduce the amount of exposure of the eyes to light between ultraviolet light and blue light having a relatively short wavelength of approximately 420 nm.
Non-Patent Document 1 describes the influence of short wavelength blue light of approximately 420 nm on the eyes.
In Non-Patent Document 1, damage to retinal nerve cells (cultured retinal nerve R28 cells of rats) caused by irradiation with blue light emitting diode (LED) light having different peak wavelengths at 411 nm and 470 nm is verified. The results show that irradiation (4.5 W/m2) with blue light having a peak wavelength at 411 nm causes the cell death of retinal nerve cells within 24 hours, whereas, for blue light having a peak wavelength at 470 nm, changes do not occur in cells even when irradiated with the same amount, and show that suppression of exposure of light having a wavelength of 400 to 420 nm is important for eye disorder prevention.
In addition, there is a concern that exposure of the eyes to blue light for a long time will result in eyestrain and stress and this is considered to be a factor causing age-related macular degeneration.
Patent Document 1 discloses a plastic lens including an ultraviolet absorbing agent having an average light transmittance of 0.5% or less in a wavelength range of equal to or more than 300 nm and equal to or less than 400 nm.
Patent Document 2 discloses a method in which a benzophenone-based ultraviolet absorbing agent is added to a diethylene glycol bisallyl carbonate polymer in an amount equal to or greater than that at which the light transmittance at a wavelength of 380 nm is 0% and equal to or less than that at which a light transmittance at a wavelength of 440 nm is 90%, so as to carry out radical polymerization to manufacture a diethylene glycol bisallyl carbonate polymer.
Patent Document 3 discloses a polymerizable composition including a polymerizable allyl carbonate, a photochromic compound and an ultraviolet absorbing agent in an amount not exceeding 1 part by weight with respect to 100 parts by weight of polymerizable allyl carbonate in a polymerizable composition. Furthermore, Patent Document 3 discloses that the polymerizable allyl carbonate may include bis(allyl carbonate) of a monomer of diethylene glycol or a mixture of a monomer and oligomer, bis(allyl carbonate) of a monomer of neopentyl glycol or a mixture of a monomer and oligomer, tetrakis(allyl carbonate) of pentaerythritol, or the like.
Patent Document 4 discloses that a polymerizable composition obtained by carrying out a transesterification reaction on a mixture of diallyl carbonate and a phthalic acid ester with one or more linear type or side chain type polyols including 2 to 8 carbon atoms may include an ultraviolet absorbing agent.
Patent Document 5 discloses that a polymerizable composition which includes predetermined amounts of an allyl ester compound, a bis(allyl carbonate) compound, an organic peroxide, and an organic dye, and describes that an ultraviolet absorbing agent may be further included. In the examples, Macrolex Blue RR and Solvaperm Red BB are used as organic dyes.